RT Journal Article SR Electronic T1 Oral contraceptives do not appear to present long-term cancer harms and may even provide protection against some cancers JF Evidence Based Nursing JO Evid Based Nurs FD BMJ Publishing Group Ltd and RCN Publishing Company Ltd SP 21 OP 21 DO 10.1136/eb-2017-102771 VO 21 IS 1 A1 Tammy O’Rourke YR 2018 UL http://ebn.bmj.com/content/21/1/21.abstract AB